This invention relates in general to communications and more particularly to a system and method for designing diverse communications circuits.
Diverse routing entails the prevention of common points of failure within a network or, in cases where this is not entirely possible, identification and tracking of points of non-compliance. Without adherence to diversity requirements during the design of circuits, a network may be vulnerable to outages and other conditions that might affect the quality and availability of communications services delivered using the network. As an example, addressing the need for diversity with respect to the Signaling System No. 7 (SS7) signaling links within the public switched telephone network (PSTN), Network Operations Forum asserts in Installation and Maintenance Responsibilities SS7 Link and Trunk Installation and Maintenance Access Service that SS7 link diversity xe2x80x9cis essential to ensure the robustnessxe2x80x9d of the PSTN and a xe2x80x9clack of diversity on SS7 routes places the entire telecommunications network at risk.xe2x80x9d SS7 links and other circuits in the PSTN have become increasingly critical as long term local number portability (LNP) and other more advanced communications services continue to become available. Even more importantly, lack of diversity with respect to xe2x80x9c911xe2x80x9d or other dedicated emergency services circuits may literally place lives at risk. In many situations redundancy, although costly, may be essentially worthless without the simultaneous presence of diversity.
Diversity requirements may necessitate the assignment to diverse circuits of separate facilities (e.g., different OC48 links), diverse aspects of the physical plant underlying facilities (e.g., different cable conduits), diverse equipment (e.g., different shelves), diverse electronic components (e.g., different power sources), or any other diverse circuit elements. Through assignment separation between diverse circuits, common points of failure are reduced. However, previous techniques for manually designing circuits have been inadequate to ensure compliance with these diversity requirements or, where such compliance is impossible or impracticable, to identify and flag diversity violations for possible remediation. These inadequacies may be exacerbated if the circuit is re-designed, the circuit requires maintenance that affects its assignments, or new circuit elements become available for assignment, yet the original diversity requirements still apply. Becoming promptly aware of and then properly balancing the many perhaps competing considerations relating to diversity requirements, throughout the life cycle of the diverse circuit, may be a daunting or even impossible task for the personnel associated with the network provider. As a result, previous techniques requiring manual diversity validation are inherently less reliable than many network providers would prefer, given the very high economic stakes. Such techniques are also relatively slow, inefficient, and therefore costly to network providers. As network providers seek to respond more rapidly to an ever expanding demand for circuits, these and other problems have become increasingly significant, making previous techniques for diverse circuit design inadequate for the needs of many network providers.
According to the present invention, disadvantages and problems associated with prior techniques for designing diverse communications circuits are reduced or eliminated.
In one embodiment of the present invention, a system for designing diverse communications circuits includes a diversity set identifying at least one circuit that is to be diverse from one or more other circuits in the diversity set. The system further includes one or more diversity rules applicable to two or more circuits belonging to the diversity set. A diversity engine validates the assignment of at least one circuit element to a circuit in the diversity set, according to the diversity rules, such that the circuit is diverse from at least one other circuit in the diversity set with respect to the circuit element. In a more particular embodiment, the circuit element is a member of a hierarchy and the diversity engine validates the assignment of the circuit element according to its position in the hierarchy and a position in the hierarchy at which a common point of failure is shared between the circuit element and another circuit element. The diversity engine may generate one or more diversity violations if the assignment of the circuit element fails to comply with the diversity rules and may associate the diversity violations with the circuit and its diversity set to indicate a possible need to modify the assignment.
The present invention provides a number of important technical advantages. Through the definition and application of diversity sets and diversity rules, and the resulting generation of diversity violations, the present invention allows the network provider to identify and enforce diversity requirements, preferably automatically, at any suitable point during the life cycle of a diverse circuit. Whether during initial circuit design, during re-design of the circuit, in connection with maintenance that affects circuit elements assigned to the circuit, or in response to availability of new circuit elements, the present invention helps network providers more efficiently and reliability protect their most vital resourcesxe2x80x94their networksxe2x80x94against the outages or other undesirable conditions that may result from common points of failure. This robustness may thus help improve the quality and availability of services delivered using the networks. Systems and methods that incorporate one or more of these or other technical advantages are well suited for modern communications networks. Other technical advantages should be apparent to those skilled in the art from the following figures, descriptions, and claims.